I appreciated finding a procedure on Encoder Motor Sensor Replacement. I purchased a sensor and gasket ($110.00) for my 2005 Chevy Silverado. I'm a basic back-yard mechanic that likes to pull wrenches on my toys now and then. It wasn't a difficult job at all. It actually went quite well. My high hopes were shattered when, within one week, the "service 4wd" message re-appeared. I then removed the negative battery cable for about 15 minutes hoping the on-board computer would reset itself. The message reappeared within a couple days. I then had our mechanic wizard at work remove the code with a decoder unit. The message still reappeared later. Ok, so i tried cleaning the ground wires on the frame (I recall 2 previous comments on ground wires) hoping again to resolve this issue. Nope, message reappeared. I can shut off the vehicle or clear the message using the steering wheel delete control but the message will reappear in a couple days. Ironically, the 4 wheel drive shifts to all positions and works fine. I'm baffled.....Any body have any suggestions?